Apparatus for manufacturing a semiconductor device

1. An apparatus for manufacturing semiconductor devices, comprising: a main chamber with a main heater for heating said main chamber; and a single preliminary chamber being cylindrically shaped and being provided under said main chamber, said single preliminary chamber being separated by a shutter from said main chamber, and said single preliminary chamber having a preliminary heater for heating said single preliminary chamber, said single preliminary chamber having at least a pair of doors which form a part of said single preliminary chamber.

2. The apparatus as claimed in claim 1, wherein said single preliminary chamber comprises a first half-cylinder shaped part and a second half-cylinder shaped part, and said at least one pair of doors forms said second half-cylinder shaped part.

3. The apparatus as claimed in claim 2, wherein at least one pair of hinges is further provided at opposite sides of said first half-cylinder shaped part for connecting said at least one pair of doors to said opposite sides of said first half-cylinder shaped part, so that said at least one pair of doors are hinged to said first half-cylinder shaped part.

4. The apparatus as claimed in claim 2, wherein at least one pair of arched door rails is further provided along said second half-cylinder shaped part for allowing said at least one pair of doors to slide on said arched door rails, so that said at least one pair of doors are movable around said first half-cylinder shaped part to open said at least one pair of doors.

5. The apparatus as claimed in claim 2, wherein at least one pair of straight door rails is further provided at opposite sides of said first half-cylinder shaped part and extends in diametrical and anti-parallel directions for allowing said at least one pair of doors to slide on said straight door rails, so that said at least one pair of doors are movable in said diametrical and anti-parallel directions.

6. The apparatus as claimed in claim 1, wherein said preliminary heater is capable of heating said single preliminary chamber up to substantially the same temperature as said main chamber.

7. The apparatus as claimed in claim 1, wherein said preliminary heater is provided around a side wall of said single preliminary chamber.

8. The apparatus as claimed in claim 1, wherein said semiconductor wafers are mounted on a wafer boat which is moved by a boat elevator between said main clamber and said preliminary chamber, and said at least one pair of doors is opened to allow said semiconductor wafers are picked up from said wafer boat set in said preliminary chamber.